According to tech firm Nuage's managing director David Wilson, some employers are asking to view Facebook and Twitter profiles at interviews in order to avoid privacy concerns.

"The internet has a very long memory. An ill-advised or impulsive post can be rapidly replicated across many sites and be impossible to take back," Wilson said.

"People really do enjoy the freedom of expression on social media, but it is worth considering the cumulative effect of their postings," he added.

Australia's National Crime Check managing director Martin Lazarevic said the variety of employers getting police checks on applicants had grown rapidly in the past six months, and as many as one in ten checks were catching people out.